A COULOGRAVIMETRIC INVESTIGATION OF ZINC ELECTRODE IN POTASSIUM HYDROXIDE

The presented results obtained by weighing the zinc electrode in the electrolyte during the discharge cycle agree with data of others and explain why the capacity of the zinc electrode is a function of the amount of electrolyte used and roughly linearly dependent on the concentration of the potassium hydroxide up to about 10M. Previous results, that part of the zinc goes into solution, part is precipitated out as oxide or hydroxide, and that some adherent layer is formed which finally forces the potential of the plate to drop sharply, are substantiated on a more quantitative basis. The experiments also indicate that the relatively thick scale formed might not be the sole cause of the passivation phenomena. © 1968, The Electrochemical Society, Inc. All rights reserved.